136 Observations on (he 



of Paris. The observations of both these gentlemen are made 

 use of by M. Decandolle in his Prodromus regni vegetabilis* 

 Mr. Ntittall, in his Genera of North American plants, always 

 judicious, has collected many facts relative to the species 

 which he had an opportunity of seeing. As the present pub- 

 lication pretends to contain nothing more than my own per- 

 sonal knowledge, which I have mentioned as being by no 

 means perfect, no species will be introduced among my de- 

 scriptions which I have not myself examined particularly. 

 In the pursuit of Natural History I early learnt to doubt, and, 

 finding that I often led myself astray, to distrust the observa- 

 tions of others : compilation has therefore been avoided. 

 What I have attempted to do may not be satisfactory, but it 

 is hoped that all botanists will be content with my endeavours 

 to elucidate so obscure a subject. After all, in a family of 

 plants so nearly related as the Violets are, where few species 

 are found so distinct as not to run into each other, it is a diffi- 

 cult matter to be pleased with any distribution. 



The American Violets, like these of every other country, 

 are divided into two great families ; the so-called stemless, 

 and the caulescent. Of the first I shall describe nineteen 

 sorts, and of the other eight. But few characters exist in 

 any that can be considered as decidedly and strictly constant. 

 The relative proportion of the parts cannot be depended 

 upon : the villosity of one or more of the petals continually 

 varies ; pubescence is found in some at one period of the year 

 and not at another, and a plant which in one situation is 

 smooth, becomes hairy from some change either of place or 

 of soil ; entire and divided leaves are found upon the same 

 plant either at the same time or at different periods of its 



* By a curious mistake Mr. Schweinitz is always quoted by Decandolle 

 as Mr. Lewis, the name being taken for the surname, as if one were to 

 quote M. Decandolle, as M. Auguste. 



